The proposed research seeks to increase understanding of the role of self-regulation in promoting resiliency to the influence of deviant peers and the associated development of substance use during adolescence and emerging adulthood. Adolescence represents a critical developmental period during which longitudinal trends toward a variety of serious health-risking behaviors can be established. Exposure to deviant peers during adolescence has been widely demonstrated to play a powerful role in shaping adult outcomes, particularly growth in substance use. Evidence of deviant peer influence has been identified on several levels, including in dyadic interactions with a peer and in exposure to a broader deviant peer group (e.g., Dishion, Spracklen, Andrews, & Patterson, 1996; Elliott, Huizinga, & Ageton, 1985). Further, these influence processes may promote iatrogenic intervention effects in aggregated youth (Dishion & Dodge, 2005). Less is know about individual characteristics that promote resistance to influence of deviant peers. The ability of adolescents to self-regulate or modify and maintain control over their behavior has been consistently negatively associated with a variety of problem behaviors, including substance use and abuse. However, only recently has it been investigated in the context of exposure to peer influences. Adolescents' surveyed temperamental traits associated with self-regulation have been found to be predictive of resiliency to exposure to deviant peers (Gardner, Dishion, & Connell, under review; Piehler & Dishion, in preparation; Wills, Sandy, Yeager, & Shinar, 2001). The proposed research seeks to study adolescent self-regulatory ability in the context of videotaped interactions with friends. Self-regulation in interpersonal situations has been identified as an important yet underdeveloped area of study, and it has been found to be specifically related to susceptibility to other domains of social influence (Vohs & Ciarocco, 2004). In order to examine the role of adolescents' interpersonal self-regulation in developing resiliency to deviant peer influences, the proposed study will seek to create and validate a coding system to assess these abilities during direct observation of friendship interaction and influence. In relation to public heath, adolescent substance use is associated with a plethora of significant public health concerns, including criminality and substance abuse and dependence, and further represents risk for escalation of these behaviors into adulthood. By better understanding what individual protective factors may be associated with lessening the influence of deviant peers, we may be able to more effectively promote resiliency through well-targeted interventions. [unreadable] [unreadable] [unreadable]